1. Field of the Invention
The invention relates to a smoking article and to a process for filtering tobacco smoke which employs a particulate solidified cross-linked organic oil to filter tobacco smoke. The invention also relates to a novel filter material comprising a particulate solidified cross-linked organic oil in combination with an organic or inorganic powder which serves as a bulk flow-improving agent.
2. Prior Art
At present, one of the most widely used filter materials for tobacco smoke is a crimped tow of plasticized cellulose acetate which has acceptable efficiency for removal of total particulate matter (TPM) from cigarette smoke at low resistance to draw (RTD) and is relatively low in cost and easy to fabricate. The cellulose acetate tow is especially adaptable to high speed fabrication. However, many materials have been suggested or tried in efforts to provide efficient tobacco smoke filter materials (i.e., materials providing a higher TPM removal/RTD ratio) which would still meet the other criteria set forth above. Some of the materials which have been tried or suggested are porous or microporous resins such as polyurethanes, polyacetals, styrene or vinyl chloride polymers; however, none of these materials are completely satisfactory. Many of these materials are relatively high in cost; some do not possess the bulk flow characteristics required in the manufacture of tobacco smoke filters from these resins, and others are ineffective except in a form especially prepared for this end use.